Radiator Thermostat valves are often overlooked. That is because they appear to be a minor element in radiator installations. Additionally, radiator valves are an essential component of any radiator purchase. And, they come in various styles and types.

New radiators are an excellent way to improve the performance of your heating system. Moreover, modern systems offer significant cost savings. Installing the correct radiator thermostat valve will significantly impact your new radiator efficiency. That is because you have more control over your heating.

Any heating system's radiator valve is an essential factor. It ensures that your system is operating at peak efficiency. So, you get superior comfort in residential and commercial settings.


What is a radiator thermostat?

What is a radiator thermostat?

Thermostatic Radiator Valves, also known as TRVs, control the room air temperature. It automatically adjusts the hot water amount entering the connected radiator. Thus, it becomes easier and more cost-effective to create a warm environment.

You may have only one centralised boiler system as the primary heat source. But, you can create different heating zones throughout the house. All you have to do is install the thermostatic radiator valve correctly.

You can install a TRV on a radiator in a hot-water or steam heating system. Further, it allows you to control the temperature of that specific radiator. As a result, you have more control over the room temperature and comfort.

How does a radiator thermostat work?

A radiator thermostat is a self-regulating system. It works by adjusting the hot water flow into your radiator. It's a fairly straightforward mechanism, consisting of two main components. They are the valve body and the valve head, with the head resting on top of the body.

When the temperature in the room begins to change, a capsule in the TRV's head expands or contracts. To illustrate, it automatically moves a pin in the valve's body, causing the valve to open or close. Likewise, the capsule will contract and pull out the pin if the temperature in your room drops too low. In this way, it permits more hot water to enter your radiator and raises the temperature. If the room becomes too warm, the pin will close the valve and reduce the hot water flow. 

The capsules in TRV adjust the temperature using a metal spring filled with liquid or wax. Out of the two, the liquid type is the best and most consistent since they are far more responsive. Wax can take a long time to expand and contract. On the other hand, liquid TRVs change water flow into the radiator much faster.

What is the difference between manual and thermostatic radiator valves?

Radiator valves are found at inlet and outlet pipes, mostly at the bottom of a radiator with a twisting mechanism on top. They let you control how much heat your radiator emits, similar to how a tap controls water flow.

There will be two valves on each radiator. One regulates the amount of hot water that enters the radiator. The other maintains system balance by regulating the heat leaving your radiator. The 'lockshield valve' is what it's called. The lockshield valve has a plastic cap over its head. It manages the amount of water that flows out of your radiator. This can either be left inside the radiator or redirected back into the pipework. You cannot turn the lockshield valve as it is usually fixed.

The radiator valves are divided into thermostatic and manual radiator valves.

Manual Radiator Valves

A manual radiator valve is one of the most common radiator valve types. The name gives away how these valves work - you must turn them to control the temperature.

They function similarly to a tap in which they control the hot water flow from the boiler into the radiator. The higher the level on the valve, the more hot water will enter the radiator, producing more heat. You will need to turn the valve down to a cooler setting once the room has reached the desired temperature. 

Thermostatic Radiator Valves

This type of radiator valve is known as TRV (Thermostatic Radiator Valves). They give extensive control to manage the room temperature. You can calibrate the valve with the temperature you wish to have, just like a manual valve. However, they have more advanced features.

The thermostatic valve detects the temperature in your room. Once the desired temperature is reached, it shuts off the flow of hot water to your radiator. Thus, it prevents it from becoming warmer and wasting heat and energy.

Manual valves are less complicated to operate than thermostatic valves. Also, they are generally smaller in size. But since they are manual, you must remember to turn them off when you are not using them. Otherwise, you'll be spending energy and money on the heat you don't require.

Thermostatic valves are the radiator valves of the twenty-first century. They allow the radiator to operate on its own for the most part. This means you don't have to worry about turning the valve off yourself because the TRV will take care of it. This will save you money and prevent you from wasting heat. As a result, it benefits both your heating costs and the atmosphere.

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Do I need a room thermostat with thermostatic radiator valves?

Yes! The best way to get your home's heating just right is to use thermostatic valves! When used with a room thermostat, they perfectly regulate your heating. It ensures that no rooms are overheated.

Plus, you'll save money on energy.

The room thermostat measures the temperature of the room in which it is installed. If the temperature in this room isn't quite right, the thermostat will send a signal to your boiler. Then, it will make it run until the desired temperature has been reached.

How to install a radiator thermostat valve?

Let's look at how to install a thermostatic radiator valve in three easy steps. You can use the same steps to replace the TRV.

Step 1: Remove the air from your system and drain it.

Drain your heating system. Allow air to circulate through all radiators where TRVs will be installed. Then, using a bleed key and a hose, bleed your radiators. When the water stops running, it's time to take out the old valve.

Step 2: Remove the old valve

To expose the simple on/off valve:

  • Remove the top cover.

  • Slacken the nut that is coming out of the radiator pipework with grips and an adjustable spanner. When it's loose, you can pull the pipework out to see if the system is completely dry.

  • Loosen the 15 mm pressure fitting on the valve's bottom. Now, the entire valve is removable from the radiator pipe.

Step 3: Install the new radiator thermostatic valve

The new TRV may not fit on the current valve insert sometimes. They include a new insert with all new TRVs. At such times, you may need to remove the old one. Use an adjustable spanner to loosen the part after inserting a simple hex tool into the hole. Wrap the new insert in PTFE, press it inside the radiator, and fasten it. You can use the old nut and olive. But, simply remove the nut and pull the olive with a pair of grips if you want to switch them out.

Step 4: Turn on the water supply

It's time to turn everything back on after you've tightened all the loose ends. Close all radiator valves, including the bleed valve, that you've opened.

Replace the heating system by turning on the water supply. Watch out for any leaks in the new joints. When you feel everything is set, turn on the new radiator valve. Allow the water to flow into the radiator. Everything should be fine if there are no leaks.

Replacing a radiator thermostat

The process of replacing the radiator thermostat is the same as installing one. Follow the same process, and you can easily replace the radiator thermostat. However, not that removing the existing radiator thermostat head can be a problem. The type of radiator head determines how to remove it. So, check the type of radiator head and then proceed. 

Common problems of thermostatic radiator valves

The thermostat can fail.

The thermostat isn't depressing if the valve works and the plunger moves freely. It is releasing the plunger, causing the valve to open and close improperly. The thermostat is a relatively simple device. It moves the plunger by expanding and contracting the wax or liquid. This movement is in coordination with the changes in temperature.

How to check if the thermostat has failed?

If the thermostat has stopped working, you have no choice but to replace it. Before you go out and buy a new one, double check to know if this is the only issue. You can replace the thermostat with a working TRV and validate.

If your radiator valve runs with battery power, consider replacing batteries.

The radiator valve sticks or catches.

This is the most common and recurring problem with a thermostatic radiator valve. The valve or the valve's head sticks or catches.

This can happen if the valve setting hasn't been adjusted in a long time, such as at the end of a long hot summer.

How to unstick a radiator thermostatic valve?

If the pin in the valve hasn't failed and the valve head isn't completely immovable, this is a simple fix. It shouldn't cost you any additional money.

To remove the top of the TRV, undo the large thumbwheel just above the radiator tail. Turn the TRV to its highest setting, usually displayed as the number 5. This fully opens the valve. This is an easy task and does not need a wrench to complete.

After opening the valve, you would see a small metal pin. It normally moves up and down once it's been removed.

If it's sticking or catching, spray some WD40 on it and work it around until it slides freely. An annual inspection and WD40 spray are recommended to keep the TRV in good working order.

If you can't get the plunger to work again, the valve has failed and must be replaced entirely.

Places you shouldn't use thermostatic radiator valves

You should not install the thermostatic radiator valves in the same room where you have installed the boiler thermostat. If the temperature of TRV is set below the boiler temperature, the TRV would turn the radiator off before the boiler’s temperature is reached.

You should inspect your thermostatic valves every year even when they are self-operating. They do not require your attention as much as a manual valve. But, you should ensure that they are still functioning properly.

What is a smart radiator valve?

Smart radiator valves have temperature settings that can be controlled from your mobile device. That means, you can set the temperature in each space to your liking, whether you're inside or outside.

Smart Radiator Valves measure the room temperature using integrated temperature sensors. They cut the room temperature to the setpoint temperature. This controls the flow of hot water into a single radiator. It follows the same process as that of the traditional thermostatic radiator valve.

tado° introduces a wide range of Smart Thermostats. While each comes with various easy-to-use features, the Child Lock feature makes tado° Smart Thermostats special.

When enabled, tado° will ignore any changes made manually to Smart Radiator Thermostat. That keeps you free from worrying about the changes that your child can make.

Wi-Fi radiator thermostat

The Wi-Fi radiator thermostats are the smart thermostats that come with Wi-Fi technology. It enables you to manage your central heating system remotely with Wi-Fi.

tado˚ smart radiator thermostat

The tado˚ smart radiator thermostat is more than just a simple thermostat. It includes advanced algorithms, sensors, Wi-fi, and several other features. In addition, the thermostats have built-in learning capabilities. They can "learn" when people are active. They heat or cool as required using their sensors, by adjusting their schedules. You can also find several branded mobile apps already integrated with smart thermostats. So, you can adjust the temperature from anywhere with a data/Wi-Fi connection.

Why are tado˚ Smart Radiator Thermostats better?

tado˚ Smart Radiator Thermostats are specifically designed to intelligently control temperature. It is devised to ensure that your home is always exactly how you want it.

tado˚ smart thermostat assists in managing your home's heating by learning your habits. They understand your routine and heat your home to the appropriate temperature.

Here is how tado˚ Smart Radiator Thermostats are better.

Reduced heating bills

The information provided by the tado˚ smart thermostat is both accurate and useful. You can create a schedule with the correct temperature zones to save money on energy bills. tado˚ smart thermostat can give you more control by heating your home when it is needed. The tado˚ Auto-Assist, an optional additional feature with a monthly subscription, determines the best times for turning on your heating and hot water. It allows you to achieve the perfect temperature quicker and more effectively.

Multi-Room Control

With tado° Smart Thermostat, you can create different zones in the house and control the temperature of each zone separately with just a single app. That is to say, every radiator equipped with a tado° Smart Thermostat can be controlled via one app.

Programmable thermostatic radiator valve

The tado˚ smart thermostat comes with in-built programmable features, including

Voice command

It's compatible with most smart home platforms. Further, you can control it using voice commands. Integrate with Amazon Alexa, Google Assistant, Apple Siri, etc.

Smart Schedules

The tado˚ app enables you to set your desired temperatures for every room at any particular time from anywhere according to your routine.

Tracking energy usage

It can provide you with energy reports that show how much energy you're consuming. They also show how your energy consumption has changed over time and how much it will cost you.

Replacing radiator thermostats with tado˚ Smart Radiator Thermostats

Standard TRVs can improve energy consumption since you can adjust the radiator temperature. This is usually a manual system with a 0-to-5 scale for changing the heating levels. What if you have the ability to set different temperatures in different rooms with one click in the app, from wherever you are? A Smart radiator thermostat can help with that!

Smart TRVs give you far more control over your home's heating. You can control the temperature in each room individually to save energy. These TRVs together with a thermostat app can optimise the heating and energy usage. This, in turn, helps lower your household bills while keeping everyone comfortable.

So, get easy on your pocket and nature, and install tado˚ Smart Radiator Thermostats.